SHARPENING MACHINE FOR SHARPENING OF CUTTING EDGES OF INSTRUMENTS, E.G. DENTAL INSTRUMENTS

Abstract: Sharpening machine for sharpening of cutting edges of instruments, e.g. dental instruments. The machine comprises a rotating grinding disk with supports that makes it possible to reproduce inner and outer grinding facets with close accuracy, and where parts to be contaminated can be dismounted for sterilization with no use of tools.

Description: Sharpening machine for sharpening of cutting edges of instruments, e.g. dental instruments The invention refers to an apparatus of the in the introduction of Claim 1 described type. From the United States Patent Application No. 1,556,471 a similar apparatus is known. This well-known apparatus is suitable for shaφening the edges of instruments with outer cutting edges. However, it is not possible to shaφen instruments with inner, curved cutting edges of different cutting angles. The reproduction of the outer grinding angles is also doubtful, as it is not stated where to place the cutting edge on the grinding disk during the grinding process. The requirements of hygiene in connection with e.g. dental intruments cam ot be met by this well-known technique, either. The purpose of the invention is to present an apparatus of the above mentioned well-known type, but by which the disadvantages of the well-known technique are rectified. According to the invention this is obtained by an apparatus, which is characteristic of what is stated in the characterizing part of Claim 1. By designing the apparatus this way the adjustment of the distance of the instrument from the axis of rotation makes it possible to grind the inner cutting edge by an arbitrary wedge angle. By designing the extended axle, as described in Claim 2, a suppport is obtained, by which a specific wedge angle can be reproduced very simply by choosing a suitable diameter of the shaft extension. The in Claim 3 described design makes it possible to extend the axle of the grinding disk in a very simple way. By designing the apparatus as described in Claim 4, the entire parts of the apparatus can be dismounted to be sterilized and remounted in a simple way. The in Claim 5 described design of the grinding disk is especially advantegeous, because it ensures an acceptable rotation without twisting (uneven running), wliich is very important especially for dental instruments with inner cutting edges. By removal of tartar and smoothening of root cement it is important that the cutting edge is shaφ and regular with no cuts or grinding checks. The in Claim 6 described placement of the instrument above the diagonal line of the grinding disk makes it possible with close accuracy of repetition to shaφen the cutting edge of the outer shaφened facet. The in Claim 7 described design makes it possible to start the grinding process very advantegeously without touching the apparatus itself. Consequently, the risk of contamination is minimized, when the grinding process is carried out during the treatment of patients . The invention will be further explained below, with reference to the drawings, described in the following: Fig. 1 shows the grinding disk mounted on the driving shaft, displayed from the side with an shaft extension, which is to set off the instrument in relation to the diagonal line of the grinding disk. Fig. 2 shows that the radius of the grinding disk is shorter than the radius of curvature of the instrument. Fig. 3 shows the grinding disk seen from above with the extended axle, providing the offset angle in relation to the diagonal angle. The larger displacement, the larger angle. Fig. 4 shows the shaφener displayed from the side, an instrument to be shaφened being placed on the outer facet of the cutting angle, the surface making up the clearance angle. The instrument is supported by a support sheet that is activating the direction of rotation. Fig. 5 shows an enlargement of the same as Fig. 4, and the cutting edge is placed in the diagonal line, when the instrument is placed against the diagonal stop. Fig. 6 shows the grinding disk seen from above with the instrument placed for outer grinding. The grinding direction is chosen individually. Word list 1. Grinding disk 2. Driving shaft 3. Shaft extension 4. Instrument 5. Cutting angle 6. Radius of grinding disk 7. Outer cutting edge 8. Support sheet 9. Sensor 10 . Support point 11 . Diagonal line 12 . "Off set" distance = angle 13 . Point of fixation 14. Diagonal stop

Claims: Patent claims Shaφening machine for shaφening of cutting edges of instalments, e.g. dental instruments, and of a type provided with a rotable grinding disk mounted on a vertical axle, including an essential upwards turned grinding surface and a support sheet, against wliich the instrument can be supported without hinderance in a chosen angle in relation to the disk, when the cutting edge of the instrument is placed above the diagonal line of the grinding disk, while the instrument is in touch with the grinding part of the disk. 1. The apparatus according to Claim 1 is characterized by the fact that the axle of the grinding disk can be extended above the plane surface of the disk and form a support of the instrument, the longitudinal axle of the instrument being displaced radially away from the axis of rotation, and by the fact that moreover the grinding disk is designed with a grinding periphery, winch in an axial cut has a circular cross section with a radius that is shorter than the radius of curvature of the cutting edge of the instrument. 2. The apparatus according to Claim 2 is characterized by the fact that the support is foπned by a shaft extension, which decides the wedge angle by its diameter. 3. The apparatus according to Claim 3 is characterized by the fact that the shaft extension is mounted in the hub bore of the grinding disk in extension of a driving shaft. 4. The apparatus according to Claim 4 is characterized by the fact that the grinding disk and instrument support of any kind that are to be contaminated while being used and consequently has to be sterilized, can be mounted and dismounted using no tools or fastening device on the connection point. 5. The apparatus according to Claim 5 is characterized by the fact that the lower part of the hub bore of the grinding disk is conically divergent against the under side of the latter and constructed to cooperate with a complementarily designed end part of the driving shaft. 6. The apparatus according to Claim 6 is characterized by having a diagonal stop, wliich secures the reproduction ability by grinding of the outer cutting facet, when the handle of the instrument is placed in a chosen support point and at the same time is in touch with the diagonal stop. 7. The apparatus according to Claim 7 is characterized by the fact that the grinding disk is activated in the correct direction of rotation, when the handle of the instrument is placed in the support sheet, to avoid formation of burrs on the cutting edge.

Inventors: LYSTAGER GREGERS, LYSTAGER, GREGERS
Applicants: LYSTAGER GREGERS, LYSTAGER, GREGERS
Application year: 1994
Main classification: B24B3
IPC codes: A61C13, A61C19, B24B3